Researchers have started to describe pseudohallucinations along a continuum. We build on this dimensional approach and suggest a collaborative nomenclature for subtyping.

Background It is clinically imperative to better understand the relationship between trauma, auditory hallucinations and dissociation. The personal narrative of trauma has enormous significance for each individual and is also important for the clinician, who must use this information to decide on a diagnosis and treatment approach. Aims To better understand whether dissociation contributes in a significant way to hallucinations in individuals with and without trauma histories. Method Three groups of participants with auditory hallucinations were recruited, with diagnoses of: schizophrenia (without trauma) (n = 18), post-traumatic stress disorder (PTSD, n = 27) and comorbid schizophrenia and PTSD (SCZ+PTSD), n = 26). Clinician-administered measures included the PTSD Symptoms Scale Interview (PSSI-5), the Clinician-Administered Dissociative States Scale (CADSS) and the Psychotic Symptom Rating Scales (PSYRATS). Results Dissociative symptoms were significantly higher in participants with trauma histories (PTSD and SCZ+PTSD groups) and significantly correlated with hallucinations in trauma-exposed participants, but not in participants with schizophrenia (without trauma history). Hallucination severity was correlated with the CADSS amnesia subscale score, but depersonalisation and derealisation were not. Conclusions Dissociation may be a mechanism in trauma-exposed individuals who hear voices, but it does not explain all hallucinatory experiences. The SCZ+PTSD group were in an intermediary position between schizophrenia and PTSD on dissociative and hallucination measures. The PTSD and SCZ+PTSD groups experienced dissociative phenomena much more frequently than the schizophrenia group, with a significant trend towards the amnesia subtype of dissociation.

History of childhood trauma and variability in derealisation/depersonalization scores were better predictors of external, negative, uncontrollable voices than diagnosis of BPD or PTSD. The potential links between dissociative states and pseudo-hallucinations are discussed.

No abstract

BackgroundResearch has supported a model of dissociation mediating the experience of hearing voices in traumatised individuals.AimsTo further understand this model by examining subtypes of the dissociative experience involved in trauma-intrusive hallucinations.MethodThe study involved four hospitals, 11 psychiatrists and 69 participants assessed using the Psychotic Symptoms Rating scale, the PTSD Symptoms Scale Interview and the Dissociative Subtype of PTSD ScoreResultsIn total, 59% (n = 41) of the participants heard voices and they were compared with the 41% (n = 28) who did not. The severity of PTSD symptoms did not predict experience of hearing voices. Regression analysis indicated that two scales of dissociation (derealisation/depersonalisation and loss of awareness) were equally good predictors of the extent of hearing voices. Adding other possible predictors (age of trauma <18, sexual violence) was relevant but did not enhance the prediction.ConclusionsThis research supports the proposal that trauma-intrusive voices are mediated by symptoms of dissociation. The supported model describes general, rather than trauma specific, symptoms of dissociation mediating the experience of hearing voices. The concept of anchoring is discussed and suggests a potential treatment strategy, which could be useful in the clinical management of hearing voices.Declaration of interestNone.